I’m [25m] currently dating the mother [38f] of my little sister’s [13f] friend [12f], and both my family and her daughter are angry about it

I’m \[25m\] currently dating the mother \[38f\] of one of my little sister’s \[13f\] friends \[12f\]. My sister and my girlfriend’s daughter have been friends since they were in elementary school. Our relationship started when my mom asked me to pick up 13f from her house about a month ago.

When I showed up, my sister and her friend were still busy trying to finish a level of the game they were playing. I wasn’t in any hurry, so I didn’t mind waiting for a bit. To pass the time, I started talking to her friend’s mother. She shared with me her life frustrations, including the problems she has been having as a divorced single mother and dealing with her ex husband and his wife. In return, I expressed my frustrations with my rather stagnant life.

Despite being in my mid twenties, I still never left my parent’s \[48f and 49m\] house. I just haven’t been to find anywhere that I could afford. I feel so trapped by this, and there really isn’t much opportunity for me to leave. Especially since my job really doesn’t pay me much, and there really much else available to me no matter how hard I looked. I’ve taken some classes, but my progress has been limited, and it was too much for me and my family to afford on a regular basis.

My greatest fear is that I’m still going to live like this even when I’m in my thirties. What twists the knife to me is that I see many of my friends from high school having families and careers of their own, while my life hasn’t changed that much since graduation. Hell, another one of my younger sisters \[22f\] has been doing well in law school so far, and is set to be married to her fiancee \[24m\] in next March. Yet here I am in my mid twenties still living like I was as a teenager.

I vented all of this to her, and she didn’t seem to judge me whatsoever. She told me that a lot of people my age are stuck in my shoes given the current state of the economy, and there really isn’t any reason for me to fret. She even mentioned that she has been struggling with the bills lately, and has considered moving in with her father.

Eventually, 13f and her friend came up the stairs, and she was ready to go. Before we went back home, I exchanged numbers with the friend’s mother. We talked a lot over texts and calls, and within a few weeks, we started seeing each other.

This is the first time I’ve been dating since 9th grade. So far, it’s been going very well. My girlfriend has been nothing but kind and loving to me, and this has been the happiest I’ve been in a while. I feel like this is also the first time in years that I’m moving forward with my life.

However, most of my family don’t approve. My parents, 22f, and her fiancee have went on and on about how my girlfriend is too old and is probably using me as her “plaything”. They also have told me that I should probably find someone with a more similar living situation.

My other siblings, 19m and 15f, have said that they think that my relationship is really weird, and keep asking me what I see in her. 13f is probably the most hostile to it out of anyone in my family. She, for whatever reason, believes that my relationship with her friend’s mom is inappropriate and that she is intruding on our family life through it. Almost every other night, she sits in my room begging me to break up with her.

My girlfriend’s children (the above mentioned friend of my sister, 10f, and 8m) also don’t seem to think highly of me. Every time I show up at their house, my sister’s friend gives me the stink eye, and the younger 2 hide in their rooms. Her ex husband and his wife also showed up once when I was there, and they made a “joke” about how “desperate” she must be for men when she hooked up with someone like me in my face.

This has also been straining 13f’s friendship with my girlfriend’s daughter. Apparently, just before thanksgiving break, they got in a fight about it at school. From what I heard, my girlfriend’s daughter called me a “worthless loser not worthy of her mom”, while my sister accused her mom/my girlfriend of being “an evil witch trying to steal away and mistreat me.” They then started hitting each other until some teacher intervened, and they both got sent to detention.

Our families made them both apologize for the comments directed at my girlfriend, me, and each other. Though it was like pulling teeth trying to get them to do so. As far as I know, the two of them haven’t been speaking since.

I had no idea that dating my little sister’s friend’s mom would cause this much drama. All I want is a good and stable relationship, and instead I got my family breathing down my neck, dealing with my girlfriend’s kids who despise me, and straining my sister’s relationship with her friend. What can I do to help my family and my girlfriend’s children be more accepting of our relationship together, or at the very least palatable their unease?

Things have been going really great with her and it feels like something that might just last, but its just the people around us that are the problem. I’m just beyond frustrated, and would love to hear some advice right now. Overall, what should I do about my problems?

TL:DR: Last month, I’ve started dating the mother of one of my little sister’s friends. Our families don’t approve, and it has been causing problems. Just would like some feedback on how this should be handled.